1. Technical Field
The present invention relates to a charging unit, a method for manufacturing the charging unit, a process cartridge and an image forming device.
2. Related Art
In an electro-photographic image forming device, a charge is firstly formed on the surface of an image carrier such as a photoconductive photosensitive body containing an inorganic or organic material, using a charging member, an electrostatic latent image is formed by a laser beam in which an image signal is modulated, and a toner image is visualized by developing the electrostatic latent image with the charged toner. And this toner image is electro-statically transferred via an intermediate transfer body, or directly, onto the recording material such as the recording sheet, and fixed on the recording material to produce a desired image.
In recent years, in the electro-photographic image forming device, a charging roll is mostly used as the charging member for charging the surface of the image carrier as the charged member. The charging roll contacts the image carrier in a state where a voltage is applied, and discharges into a minute gap with the image carrier to charge the surface of the image carrier. The charging roll is strictly controlled in the resistance and shape to charge the image carrier as uniformly as possible.
In the electro-photographic image forming device using the charging member such as the charging roll, the foreign matter such as a transfer remaining toner, an additive of the remaining toner or the paper dust sticking on the surface of the image carrier enters into a nip portion between the charging roll and the image carrier, and sticks onto the surface of the charging roll to contaminate the charging roll.